The only rub with that scenario is the fact that the aux. ("secondary") bowl vent on the primary float bowl closes when the throttle is opened.
Yes, you are right about that. I've never seen that vent on a race carb (Holley) I'm thinking it was to take in cooler air rather than super heated thinner air in the air cleaner assembly that would be present during extended idle periods.
The fuel today is horrible. Front end vollatility diminishes rapidly and leaves behind lots of junk. With all the alcohol and MTBEs present you can't let it sit in your carburetor for very long otherwise it will spoil quickly and make a mess of everything.